Liquid dispensing device

Abstract

To execute contamination reduction control, with a degree corresponding to a risk that contamination may occur.SOLUTION: A control part 9 controls a conveying motor 23a and a carriage motor 63 or the like, so that conveyance processing for conveying a sheet in a conveying direction by a predetermined distance and scanning processing for making a plurality of nozzles 51 of a head 5 discharge ink while moving the head 5 in a scanning direction are executed alternately and repeatedly. The control part 9 obtains or determines at least any of a paper kind (a cut paper or a roll paper), a cumulative use length of the roll paper and a grasping situation of a paper by a conveying roller pair or the like, on the basis of detected results by a roll body sensor 71, a feeding position sensor 72, a tip position sensor 81 and a rotary encoder 82; and adjusts, as contamination reduction processing, amounts of ink discharged from the head 5 and a time interval between when starting the scanning processing and when starting the subsequent scanning processing.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a liquid ejection device having a medium storage section that stores a sheet-like medium. [Background technology]

[0002] In a device that ejects liquid onto a sheet-like medium, the sheet-like medium may come into contact with the head that ejects the liquid, causing the medium to become dirty. As a control to reduce such medium dirt (hereinafter referred to as dirt reduction control), a waiting time may be provided between ejection operations, as in Patent Document 1. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-171318 Summary of the Invention [Problem to be solved by the invention]

[0004] According to the contamination reduction control of Patent Document 1, if the operation wait time is long, the time required for the entire process may become too long, and if the operation wait time is short, the effect of contamination reduction may not be ensured. Therefore, it is desirable to keep the degree of contamination reduction control within a necessary range according to the risk of contamination occurrence.

[0005] An object of the present invention is to provide a liquid ejection device that executes contamination reduction control to a degree that corresponds to the risk of contamination occurring. [Means for solving the problem]

[0006] A liquid ejection device according to a first aspect of the present invention includes a medium storage unit that stores a sheet medium, a liquid ejection head that is capable of an ejection operation for ejecting a liquid, a movement unit that moves the sheet medium fed from the medium storage unit relative to the liquid ejection head, and a control unit, wherein the movement unit is capable of at least the first movement operation of moving the sheet medium in a first direction and a second movement operation of moving the liquid ejection head in a second direction perpendicular to the first direction, and the control unit alternately executes the first movement operation, the ejection operation, and the second movement operation, or executes the ejection operation and the first movement operation simultaneously. and adjusts at least one of the amount of liquid ejected from the liquid ejection head in the ejection operation, the time interval between the start of the ejection operation and the start of the next ejection operation when the first movement operation, the ejection operation, and the second movement operation are performed alternately, and the speed of movement of the sheet medium by the first movement operation when the ejection operation and the first movement operation are performed simultaneously, so as to suppress contact of the sheet medium with the liquid ejection head, according to medium information related to the occurrence of curl in the sheet medium and indicating at least one of the characteristics and usage status of the sheet medium fed from the storage unit.

[0007] A liquid ejection device according to a second aspect of the present invention includes a medium storage unit that stores a sheet medium, a liquid ejection head that is capable of an ejection operation for ejecting a liquid, a first pair of rollers that sandwich the sheet medium fed from the medium storage unit and move it along a predetermined transport direction, and a second pair of rollers that sandwich the sheet medium moved by the first pair of rollers downstream of the first pair of rollers in the predetermined transport direction and move it along the predetermined transport direction, and is equipped with a movement unit that moves the sheet medium fed from the medium storage unit relative to the liquid ejection head, and a control unit, wherein the movement unit is capable of at least the first movement operation of moving the sheet medium in a first direction and a second movement operation of moving the liquid ejection head in a second direction perpendicular to the first direction. The control unit alternately and repeatedly executes the first moving operation, the ejection operation, and the second moving operation, or simultaneously executes the ejection operation and the first moving operation, and adjusts at least one of the amount of liquid ejected from the liquid ejection head in the ejection operation, the time interval between the start of the ejection operation and the start of the next ejection operation when the first moving operation, the ejection operation, and the second moving operation are alternately repeated, and the speed of movement of the sheet medium by the first moving operation when the ejection operation and the first moving operation are performed simultaneously, depending on whether both of the first roller pair and the second roller pair are clamping the sheet medium or whether only one of them is clamping the sheet medium, so as to suppress contact of the sheet medium with the liquid ejection head.

[0008] In addition, a liquid ejection device according to a third aspect of the present invention comprises a medium storage section that stores sheet-like medium, a liquid ejection head capable of ejecting liquid, a moving section that moves the sheet-like medium fed from the medium storage section relative to the liquid ejection head, and a control section, wherein the moving section is capable of a first moving operation that moves the sheet-like medium in a first direction and a second moving operation that moves the liquid ejection head in a second direction perpendicular to the first direction, and the control section alternately executes the first moving operation, the ejection operation, and the second moving operation, and adjusts at least one of the amount of liquid ejected from the liquid ejection head in the ejection operation and the movement amount of the sheet-like medium in the first moving operation between the start of one ejection operation and the start of the next ejection operation, so as to suppress contact of the sheet-like medium with the liquid ejection head, in accordance with medium information related to the occurrence of curl in the sheet-like medium and indicating at least one of the characteristics and usage status of the sheet-like medium fed from the medium storage section.

[0009] Furthermore, a liquid ejection device according to a fourth aspect of the present invention includes a medium storage unit that stores a sheet medium, a liquid ejection head that is capable of an ejection operation for ejecting a liquid, a first pair of rollers that sandwich the sheet medium fed from the medium storage unit and move it along a predetermined transport direction, and a second pair of rollers that sandwich the sheet medium moved by the first pair of rollers downstream of the first pair of rollers in the predetermined transport direction and move it along the predetermined transport direction, and is equipped with a moving unit that moves the sheet medium fed from the medium storage unit relatively to the liquid ejection head, and a control unit, wherein the moving unit performs a first moving operation for moving the sheet medium in a first direction. and a second movement operation that moves the liquid ejection head in a second direction perpendicular to the first direction, and the control unit alternately repeats the first movement operation, the ejection operation, and the second movement operation, and adjusts at least one of the amount of liquid ejected from the liquid ejection head in the ejection operation and the amount of movement of the sheet medium in the first movement operation between the start of one ejection operation and the start of the next ejection operation, so as to suppress contact of the sheet medium with the liquid ejection head, depending on whether both of the first roller pair and the second roller pair are clamping the sheet medium or whether only one of them is clamping the sheet medium. [Effects of the Invention]

[0010] A liquid ejection device according to a first aspect of the present invention adjusts, as a stain reduction control, at least one of the following: the amount of liquid ejected from the liquid ejection head; the time interval between the start of a stain ejection operation and the start of the next stain ejection operation when alternating between a first movement operation, a stain ejection operation, and a second movement operation; and the speed of the first movement operation of the sheet medium when simultaneously performing a stain ejection operation and a first movement operation. This adjustment is made in accordance with at least one of the medium characteristics and usage conditions related to the occurrence of curl in the sheet medium. When curl occurs in the sheet medium, the medium is likely to come into contact with the liquid ejection head. Therefore, by adjusting the content of the stain reduction control in accordance with medium information related to the occurrence of curl, as in the present invention, stain reduction control can be performed in accordance with the curl condition. This makes it possible to perform stain reduction control to a degree appropriate to the risk of stain occurrence. Furthermore, a liquid ejection device according to a third aspect of the present invention adjusts at least one of the amount of liquid ejected from the liquid ejection head and the movement distance of the sheet medium in the first movement operation in accordance with at least one of the medium characteristics and usage conditions related to the occurrence of curl in the sheet medium. In this way, similar to the first aspect, by adjusting the content of the dirt reduction control in accordance with the medium information related to the occurrence of curl, dirt reduction control can be executed according to the curl state. Therefore, dirt reduction control can be executed to a degree that corresponds to the risk of dirt occurring.

[0011] Furthermore, a liquid ejection device according to a second aspect of the present invention adjusts, as a contamination reduction control, at least one of the following: the amount of liquid ejected from the liquid ejection head; the time interval between the start of a discharge operation and the start of the next discharge operation when alternating between a first movement operation, a discharge operation, and a second movement operation; and the speed of the first movement operation of the sheet medium when the discharge operation and the first movement operation are performed simultaneously. This adjustment is made depending on whether both of the first roller pair and the second roller pair are nipping the sheet medium or whether only one of them is nipping the sheet medium. When the sheet medium is nipped between both of the two roller pairs, the risk of the sheet medium coming into contact with the liquid ejection head between the nipping positions of the two roller pairs is lower than when the sheet medium is nipped between only one of the two roller pairs. Therefore, by adjusting the content of the contamination reduction control according to the nipping state of the two roller pairs as in the present invention, it is possible to perform contamination reduction control to a degree appropriate to the risk of contamination. Furthermore, a liquid ejection device according to a fourth aspect of the present invention adjusts at least one of the amount of liquid ejected from the liquid ejection head and the amount of movement of the sheet medium in the first movement operation, depending on whether both of the first roller pair and the second roller pair are nipping the sheet medium or whether only one of them is nipping the sheet medium. In this way, as with the second aspect, by adjusting the content of the dirt reduction control depending on the state of nipping between the two roller pairs, it is possible to execute the dirt reduction control to a degree appropriate to the risk of dirt occurring. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a schematic side view showing the internal structure of a printer according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a schematic plan view of the printer shown in FIG. [Figure 3] FIG. 2 is a block diagram showing the electrical configuration of the printer shown in FIG. [Figure 4] 10 is a table showing the relationship between the ink ejection rate and the characteristics and usage status of paper used in the stain reduction control of the printer of FIG. 1. [Figure 5]10 is a table showing the relationship between the characteristics and usage status of paper and the length of the waiting time provided between scanning processes, which is used in the dirt reduction control of the printer of FIG. 1. [Figure 6] FIG. 10 is a schematic plan view of a printer according to a second embodiment, which is another embodiment of the present invention. [Figure 7] FIG. 10 is a schematic side view showing the internal configuration of a modified example of the first embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0013] [First embodiment] A printer 100 (corresponding to the "liquid ejection device" of the present invention) according to a first embodiment, which is a preferred embodiment of the present invention, will be described below with reference to Figures 1 to 5. The up-down direction, front-rear direction, and left-right direction shown in Figure 1 are the up-down direction, front-rear direction (corresponding to the "predetermined direction" of the present invention), and left-right direction of the printer 100.

[0014] As shown in Figures 1 and 2, the printer 100 mainly comprises a housing 100a, a feed tray 1, a transport mechanism 2, a cutter 3, a carriage 4, a head 5, a moving mechanism 6, a paper discharge tray 7, a cartridge mounting unit 8, and a control unit 9.

[0015] The feed tray 1 (corresponding to the "medium storage section" of the present invention) is disposed within the housing 100a below the head 5. The feed tray 1 can be inserted into and removed from the housing 100a in the front-to-rear direction through an opening 101 formed in the front wall of the housing 100a.

[0016] The feed tray 1 can accommodate the roll R and cut sheets Kp (corresponding to the "short sheet medium" of the present invention). The feed tray 1 may be capable of accommodating both the roll R and cut sheets Kp at the same time, or may be capable of selectively accommodating either the roll R or the cut sheets Kp. The feed tray 1 has a roll support section 11 that supports the roll R, and a placement surface 12 on which the cut sheets Kp are placed.

[0017] The roll R is a long sheet of paper wound in a roll shape around the outer circumferential surface of a cylindrical core member Rc. The cut sheets Kp are shorter than the long sheets of paper that make up the roll R, and are standard sizes such as A4 and B5. The largest size of the cut sheets Kp that can be used in the printer 100 of this embodiment is A4 size paper.

[0018] A roll sensor 71 is provided slightly behind the roll support section 11. The roll sensor 71 can detect whether or not the roll R is stored in the roll support section 11 of the feed tray 1. More specifically, the roll sensor 71 detects roll paper Rp (corresponding to the "long sheet medium" of the present invention) unwound from the roll R, thereby detecting that the roll R is supported by the roll support section 11. The detection result by the roll sensor 71 is output to the control section 9.

[0019] The conveying mechanism 2 includes a feeding roller 21 , a pair of intermediate rollers 22 , a pair of conveying rollers 23 , a pair of paper discharge rollers 24 , and a guide member 25 .

[0020] The feed roller 21 feeds roll paper Rp unwound from the roll R supported by the roll support section 11 or cut paper Kp placed on the placement surface 12 from the feed tray 1. In the following description, when there is no need to distinguish between roll paper Rp and cut paper Kp, they will be referred to as "paper P" (corresponding to "sheet-like medium" in the present invention).

[0021] The feed roller 21 is rotated by the drive of a feed motor 21a (see FIG. 3). When the feed motor 21a is driven under the control of the control unit 9, the feed roller 21 rotates, and a conveying force is applied from the front to the rear to the paper P in contact with the feed roller 21. This causes the paper P to be fed out of the feed tray 1. The rear wall 15 provided at the rear end of the feed tray 1 is inclined so that the upper end is located further rearward than the lower end. Therefore, the paper P fed out of the feed tray 1 is directed diagonally upward.

[0022] A feeding position sensor 72 is provided slightly behind the feeding roller 21. The feeding position sensor 72 can detect whether or not the paper P is placed at a position where it can be fed by the feeding roller 21. The detection result by the feeding position sensor 72 is output to the control unit 9.

[0023] The intermediate roller pair 22 is composed of a drive roller that rotates when driven by an intermediate motor 22a (see FIG. 3), and a driven roller that rotates along with the drive roller. When the intermediate motor 22a is driven under the control of the control unit 9, the intermediate roller pair 22 rotates while sandwiching the paper P, thereby transporting the paper P. The intermediate roller pair 22 is located above the rear end of the feed tray 1. The intermediate roller pair 22 sandwiches and transports the paper P upward, the paper P being sent out from the feed tray 1 by the feed roller 21 and heading diagonally upward. A guide member 25 is located above the intermediate roller pair 22. The guide member 25 guides the paper P transported upward by the intermediate roller pair 22 forward.

[0024] The conveying roller pair 23 (corresponding to the "first roller pair" of the present invention) is composed of a drive roller that rotates when driven by a conveying motor 23a (see FIG. 3), and a driven roller that rotates along with the drive roller. A rotary encoder 82 is provided on the driven roller of the conveying roller pair 23. The rotary encoder 82 can detect the amount of rotation of the driven roller, thereby detecting the amount of rotation of the conveying roller pair 23. The rotary encoder 82 outputs a signal indicating the amount of rotation of the conveying roller pair 23 to the control unit 9. The paper discharge roller pair 24 (corresponding to the "second roller pair" of the present invention) is composed of a drive roller that rotates when driven by a paper discharge motor 24a (see FIG. 3), and a driven roller that rotates along with the drive roller.

[0025] When the conveying motor 23a and the discharge motor 24a are driven under the control of the control unit 9, the conveying roller pair 23 and the discharge roller pair 24 rotate while sandwiching the paper P, and convey the paper P forward in the conveying direction (corresponding to the "first direction" of the present invention). The conveying roller pair 23 is located behind the head 5 (upstream in the conveying direction), and the discharge roller pair 24 is located in front of the head 5 (downstream in the conveying direction). The conveying roller pair 23 conveys the paper P guided forward by the guide member 25 further forward toward the discharge roller pair 24. The discharge roller pair 24 conveys the paper P conveyed forward by the conveying roller pair 23 further forward while sandwiching it, and discharges it onto the paper output tray 7. The operation of the conveying mechanism 2 to convey the paper P in the conveying direction by the conveying roller pair 23 and the discharge roller pair 24 corresponds to the "first movement operation" of the present invention.

[0026] A leading edge position sensor 81 is provided slightly behind the pair of conveying rollers 23. When the leading edge position sensor 81 detects the leading edge of the paper P, it outputs the detection result to the control unit 9. The timing at which the leading edge position sensor 81 detects the leading edge of the paper P is adjusted to coincide with or nearly coincide with the timing at which the leading edge of the paper P reaches the pair of conveying rollers 23.

[0027] The cutter 3 is located between the rear end of the feed tray 1 and the pair of intermediate rollers 22. The cutter 3 is made up of, for example, a disk-shaped rotary blade and a driven blade. The rotary blade of the cutter 3 is rotated by the driving of a cutting motor 3a (see Figure 3), and the cutter 3 moves back and forth in the left-right direction. The roll paper Rp that has been unwound from the roll body R and transported is cut in the width direction of the roll paper Rp by the cutter 3 when the cutting motor 3a is driven under the control of the control unit 9. This forms a trailing edge in the roll paper Rp, and the roll paper Rp is discharged to the discharge tray 7 as individual sheets.

[0028] The head 5 (corresponding to the "liquid ejection head" of the present invention) includes a plurality of nozzles 51 (see FIG. 2) formed on its underside, and a driver IC 52 (see FIG. 3). When the driver IC 52 is driven under the control of the control unit 9, ink is ejected from the nozzles 51, and when the paper P transported by the transport mechanism 2 passes an image recording position facing the underside of the head 5, an image is recorded in the ink ejection area (see FIG. 2) on the paper P. The head 5 is mounted on the carriage 4. The operation of the head 5 to eject ink corresponds to the "ejection operation" of the present invention.

[0029] The moving mechanism 6 has two guide rails 61, 62 and a carriage motor 63 (see FIG. 3). The two guide rails 61, 62 are arranged spaced apart from each other in the front-rear direction and extend in the left-right direction. The carriage 4 is arranged to straddle the two guide rails 61, 62. The carriage 4 is connected to the carriage motor 63 via a belt (not shown) or the like. When the carriage motor 63 is driven under the control of the control unit 9, the carriage 4 moves left-right (scanning direction) along the guide rails 61, 62. The scanning direction corresponds to the "second direction" of the present invention. The operation of the moving mechanism 6 to move the carriage 4 and thereby move the head 5 in the scanning direction corresponds to the "second moving operation" of the present invention. The moving mechanism 6 and the above-mentioned transport mechanism 2 constitute the "moving unit" of the present invention.

[0030] The paper output tray 7 is disposed in front of the head 5 within the housing 100a and above the feed tray 1. The paper output tray 7 can be inserted into and removed from the housing 100a in the front-to-rear direction through an opening 102 formed in the front wall of the housing 100a. The paper P on which an image has been recorded by the head 5 is received in the paper output tray 7.

[0031] 2, the cartridge mounting unit 8 is provided on one side (the right side) of the paper output tray 7 in the left-right direction, and further forward than the movement mechanism 6 in the front-rear direction. Four ink cartridges 10, each storing ink of the colors black, yellow, cyan, and magenta, can be detachably mounted in the cartridge mounting unit 8. Ink is supplied to the head 5 from the ink cartridges 10 mounted in the cartridge mounting unit 8 via a tube (not shown) or the like.

[0032] The control unit 9 controls the entire printer 100. As shown in Fig. 3, the control unit 9 is electrically connected to the feed motor 21a, intermediate motor 22a, transport motor 23a, paper discharge motor 24a, cutting motor 3a, driver IC 52, carriage motor 63, roll body sensor 71, feed position sensor 72, tip position sensor 81, rotary encoder 82, etc.

[0033] 3, the control unit 9 includes a CPU (Central Processing Unit) 91, a ROM (Read Only Memory) 92, a RAM (Random Access Memory) 93, and an ASIC (Application Specific Integrated Circuit) 94. The ROM 92 stores programs executed by the CPU 91 and the ASIC 94, various fixed data, etc. The RAM 93 temporarily stores data (image data, etc.) required when executing a program.

[0034] The various fixed data stored in ROM 92 include data indicating the size of the cut sheet Kp, the path length along the transport path of the sheet P from the cutter 3 to the transport roller pair 23, the front-to-rear distance from the transport roller pair 23 to the discharge roller pair 24, and the front-to-rear distance from the transport roller pair 23 to the image recording position by the head 5. The various fixed data also include data indicating the relationship between the number of rotations of the transport roller pair 23 and the length of the sheet P corresponding to that number of rotations. In the control by the control unit 9 described below, the length transported by the transport roller pair 23 of the sheet P is calculated based on the number of rotations of the transport roller pair 23 indicated by the detection result of the rotary encoder 82 and the above data. The various fixed data also include data indicating the tables of Figures 4 and 5 (described below).

[0035] The control unit 9 may be configured such that only the CPU 91 performs various processes, or such that only the ASIC 94 performs various processes, or such that the CPU 91 and the ASIC 94 work together to perform various processes. The control unit 9 may be configured such that one CPU 91 performs processes independently, or such that multiple CPUs 91 share the processes. The control unit 9 may be configured such that one ASIC 94 performs processes independently, or such that multiple ASICs 94 share the processes.

[0036] The control unit 9 records an image on the paper P based on a recording instruction sent by a user from an external device (e.g., a PC or smartphone). Image recording is performed by alternately repeating a transport process in which the transport mechanism 2 transports the paper P a predetermined distance (corresponding to the "first length" of the present invention) in the transport direction, and a scanning process in which the movement mechanism 6 moves the carriage 4 in the scanning direction and ejects ink from the multiple nozzles 51 of the head 5 onto the ink ejection area shown in FIG. 2. The ink ejection area shown in FIG. 2 is the area on the paper P onto which ink is ejected from the head 5 with each scanning process. This area may be an area of ​​the same length as the predetermined distance in the transport direction (corresponding to the "second length" of the present invention), or may be an area of ​​a different length (corresponding to the "second length" of the present invention). If the paper P is roll paper Rp, the roll paper Rp receives ink ejected from the head 5 while being transported by the transport mechanism 2. Meanwhile, the roll paper Rp is cut to a desired length (e.g., the length indicated by the recording instruction) by the cutter 3. As a result, the roll paper Rp becomes a single sheet of paper having the desired length (hereinafter referred to as the "cut length") on which an image has been recorded, and is discharged onto the paper discharge tray 7. If the paper P is a cut sheet Kp, the cut sheet Kp receives ink ejected from the head 5 while being transported by the transport mechanism 2. As a result, the cut sheet Kp becomes a sheet of paper on which an image has been recorded, and is discharged onto the paper discharge tray 7.

[0037] The control unit 9 controls image recording and cutting of the roll paper Rp while grasping the relative position of the paper P with respect to the conveyance roller pair 23 (hereinafter referred to as the "relative position") based on the detection results of the leading edge position sensor 81 and the rotary encoder 82. The relative position of the paper P is acquired as follows. The control unit 9 acquires the number of rotations of the conveyance roller pair 23 from the time the leading edge position sensor 81 detects the arrival of the leading edge of the paper P until a given timing, conveying the paper P by the conveyance roller pair 23, based on the detection results of the rotary encoder 82. Based on the number of rotations acquired in this way, the control unit 9 acquires the length of the paper P conveyed by the conveyance roller pair 23 from the time the leading edge of the paper P reaches (or nearly reaches) the conveyance roller pair 23 until the given timing. Based on this, the control unit 9 acquires the position ahead of the conveyance roller pair 23 of the leading edge of the paper P (roller paper Rp or cut paper Kp), that is, the relative position of the leading edge of the paper P.

[0038] For example, the control unit 9 causes the cutter 3 to cut the roll paper Rp just when the length from the tip of the roll paper Rp to the position of the cutter 3 reaches the cutting length, based on the relative position of the leading edge of the roll paper Rp and the path length from the cutter 3 to the transport roller pair 23 stored in ROM 92. Also, for example, the control unit 9 obtains the position on the paper P where image recording is being performed at any timing, based on the relative position of the leading edge of the paper P and the distance from the transport roller pair 23 to the image recording position stored in ROM 92.

[0039] Incidentally, when recording an image on paper P, a phenomenon may occur in which, when ink ejected from the head 5 reaches the paper P, the paper P lifts up and comes into contact with the head 5, staining the paper surface. The control unit 9 executes stain reduction control to prevent such problems from occurring. The stain reduction control according to this embodiment includes (1) control to reduce the amount of ink ejected from the head 5, and (2) control to provide a waiting time between one scanning process and the next scanning process during image recording. The control unit 9 executes either or both of (1) and (2) as stain reduction control when preset execution conditions are met. Examples of the execution conditions include a certain amount of time having passed since the previous execution, or a user issuing an instruction to execute stain reduction control via a recording instruction from an external device, etc.

[0040] Additionally, the control unit 9 of this embodiment adjusts the parameters for dirt reduction control as follows, based on the various detection results input from the roll body sensor 71, the feeding position sensor 72, the leading edge position sensor 81, and the rotary encoder 82. To adjust the parameters, the control unit 9 performs the following processes of determining the paper type, acquiring the cumulative usage length, and acquiring the roller clamping status based on the various detection results. The paper type information acquired by the following processes corresponds to "medium information indicating the characteristics of the sheet medium" in this invention. Furthermore, the cumulative usage length information corresponds to "medium information indicating the usage status of the sheet medium" in this invention.

[0041] As a paper type determination process, the control unit 9 determines whether the paper P fed from the feed tray 1 by the feed roller 21 is roll paper Rp or cut paper Kp. This determination is made based on the detection results of the roll body sensor 71 and the feed position sensor 72. Specifically, if the roll body sensor 71 detects that the roll paper Rp is supported by the roll body support unit 11 and the feed position sensor 72 detects that the paper P is located at the feed position, the control unit 9 determines that the paper P fed by the feed roller 1 is roll paper Rp. On the other hand, if the roll body sensor 71 detects that the roll paper Rp is not supported by the roll body support unit 11 and the feed position sensor 72 detects that the paper P is located at the feed position, the control unit 9 determines that the paper P fed by the feed roller 1 is cut paper Kp. Note that the determination may be made based solely on the detection result of the roll body sensor 71 as to whether the roll paper Rp is supported by the roll body support unit 11. In addition to or instead of the detection results of the roll body sensor 71 and the feeding position sensor 72, a determination may be made based on whether the recording instruction sent from an external device instructs recording on roll paper Rp or cut paper Kp.

[0042] To obtain the cumulative usage length, the control unit 9 calculates the cumulative usage length since the roll paper Rp on the roll body support unit 11 was first unwound and used. This calculation is performed based on the detection results of the roll body sensor 71, the leading edge position sensor 81, and the rotary encoder 82. Specifically, the control unit 9 detects from the detection result of the roll body sensor 71 that the roll paper Rp has switched from a state in which it is not supported by the roll body support unit 11 to a state in which it is supported by the roll body support unit 11. This detects that the roll paper Rp has been first unwound and used.

[0043] Next, the control unit 9 adds up the length of the roll paper Rp that has been conveyed by the conveyance roller pair 23 up to an arbitrary point in time since the roll paper Rp was first unwound and used, based on the detection results of the rotary encoder 82. Based on the result of this addition, the control unit 9 calculates, for example, at least one of the following first to third cumulative usage lengths.

[0044] The first cumulative usage length is the cumulative usage length up to the leading edge of the roll paper Rp being transported at a certain timing by the transport mechanism 2. This cumulative usage length corresponds to the value indicated by the integration result up to just before the leading edge of the roll paper Rp at that timing reaches the transport roller pair 23.

[0045] The second cumulative usage length is the cumulative usage length up to the rear end of the roll paper Rp being transported at a certain timing by the transport mechanism 2. This cumulative usage length corresponds to the sum of the cut length of the roll paper Rp and the integration result up to just before the leading edge of the roll paper Rp at that timing reaches the transport roller pair 23.

[0046] The third cumulative usage length is the cumulative usage length up to the position where image recording is being performed on the paper P at a certain timing. This cumulative usage length corresponds to the sum of the integration result up to just before the leading edge of the paper P during image recording reaches the transport roller pair 23, plus the length from the leading edge of the paper P to the position where image recording is being performed at that timing. The position where image recording is being performed is any position within the ink ejection area in FIG. 2 in terms of the transport direction. The position where image recording is being performed is obtained based on the relative position of the leading edge of the paper P obtained based on the detection results of the leading edge position sensor 81 and the rotary encoder 82, and the distance from the transport roller pair 23 to the image recording position stored in ROM 92.

[0047] As part of the roller clamping status acquisition process, the control unit 9 determines at any time during image recording whether the paper P is being clamped between both the conveying roller pair 23 and the paper discharge roller pair 24 or between only one of them. This determination is made based on the detection results of the leading edge position sensor 81 and the rotary encoder 82. Specifically, the control unit 9 detects whether the paper P is being clamped between both the conveying roller pair 23 and the paper discharge roller pair 24 or between only one of them, based on the relative position of the leading edge of the paper P and the length of the paper P (the length of the cut paper Kp stored in ROM 92 or the cut length of the roll paper Rp).

[0048] The control unit 9 adjusts the ink ejection amount in the stain reduction control (1) based on the data shown in the table of FIG. 4 stored in the ROM 92. The table of FIG. 4 shows the relationship between the paper type (cut paper / roll paper), the range of cumulative usage length (0-10 m / 10-20 m / 20 m or more), the roller clamping status (1 roller / 2 rollers), and the rate indicating the ink ejection amount after adjustment (hereinafter referred to as the "ejection amount rate"). The paper type indicates whether the paper P transported by the transport mechanism 2 is cut paper Kp or roll paper Rp. The range of cumulative usage length indicates whether the value falls within the range of "0-10 m," "10-20 m," or "20 m or more" for any one of the first to third cumulative usage lengths. The "1 roller" roller clamping status indicates that the paper P is clamped between only one of the transport roller pair 23 and the paper discharge roller pair 24. The "two rollers" in the roller clamping status indicates that the paper P is clamped between both the conveying roller pair 23 and the paper discharge roller pair 24. The ejection amount rate indicates the ratio of the ink ejection amount when the dirt reduction control is performed to the ink ejection amount when the dirt reduction control is not performed, expressed as a percentage. The smaller the ejection amount rate, the greater the degree of reduction in the ejection amount.

[0049] The degree of reduction in the discharge amount indicated by the discharge rate rate in the table of FIG. 4 is higher for roll paper than for cut paper. For example, when the roller clamping condition is "one roller," the discharge rate rate for cut paper is 90%, while the discharge rate for roll paper is 60-80%. When the roller clamping condition is "two rollers," the discharge rate rate for cut paper is 100%, while the discharge rate for roll paper is 65-85%. Furthermore, the degree of reduction in the discharge amount indicated by the discharge rate rate in the table of FIG. 4 increases as the cumulative usage length increases, and is higher for the roller clamping condition "one roller" than for "two rollers." For example, when paper P is cut paper, the discharge rate rate for "two rollers" is 100%, while the discharge rate for "one roller" is 90%. When the paper P is roll paper, the discharge rate for "two rollers" is 85%, 75%, and 65% as the cumulative usage length increases, whereas the discharge rate for "one roller" is 80%, 70%, and 60% as the cumulative usage length increases.

[0050] The control unit 9 obtains a discharge rate from the table in FIG. 4 based on the determination results and calculation results from the processes of determining the paper type, obtaining the cumulative usage length, and obtaining the roller clamping status, and controls image recording so as to reduce the ink discharge rate at the obtained discharge rate. Specifically, the control unit 9 adjusts the ink discharge rate from the head 5 so that the amount of ink that would be discharged from the head 5 in the absence of dirt reduction control is reduced in accordance with the discharge rate obtained from the table in FIG. 4. This discharge rate adjustment is applied to one sheet of paper P (one cut sheet Kp or one sheet of roll paper Rp separated from the roll R) that is the target of image recording at the timing when dirt reduction control is executed. When either the first or second cumulative usage length is used as the cumulative usage length, the discharge rate is adjusted for the entire sheet of paper P so that it is uniformly reduced by the discharge rate obtained based on the first or second cumulative usage length. Furthermore, when the third cumulative usage length is used as the cumulative usage length, the third cumulative usage length is acquired for the position where the scanning process is performed (i.e., the next image recording is performed) each time a scanning process is performed, and each scanning process is performed while reducing the ink ejection amount at the ejection rate according to the table in Fig. 4 corresponding to the acquired third cumulative usage length.

[0051] The control unit 9 also adjusts the length of the waiting time for the dirt reduction control (2) based on the data shown in the table of Fig. 5 stored in ROM 92. The table of Fig. 5 shows the relationship between the paper type (cut paper / roll paper), range of cumulative used length (0-10m / 10-20m / 20m+), roller clamping status (1 roller / 2 rollers), and the length of the waiting time. The meanings of the paper type, cumulative used length, and roller clamping status in the table of Fig. 5 are the same as those in the table of Fig. 4. The times in the table indicate the length of the waiting time provided between one scanning process and the next scanning process when dirt reduction control is performed.

[0052] The waiting time shown in the table of FIG. 5 is longer for roll paper than for cut paper. For example, when the roller clamping state is "one roller," the waiting time for cut paper is 0.5 seconds, while the waiting time for roll paper is 1.5 to 3.5 seconds. When the roller clamping state is "two rollers," the waiting time for cut paper is 0 seconds, while the waiting time for roll paper is 1 to 3 seconds. The waiting time shown in the table of FIG. 5 also increases as the cumulative usage length increases, and the waiting time for "one roller" is longer than that for "two rollers." For example, when paper P is cut paper, the waiting time for "two rollers" is 0 seconds, while the waiting time for "one roller" is 0.5 seconds. When paper P is roll paper, the waiting time for "two rollers" is 1 second, 2 seconds, or 3 seconds as the cumulative usage length increases, while the waiting time for "one roller" is 1.5 seconds, 2.5 seconds, or 3.5 seconds as the cumulative usage length increases.

[0053] The control unit 9 obtains the length of the waiting time from the table in FIG. 5 based on the determination results and calculation results from the processes of determining the paper type, obtaining the cumulative usage length, and obtaining the roller clamping status, and controls image recording so that the obtained waiting time is set between scanning processes. Specifically, the control unit 9 adds a period during which both ink ejection from the head 5 and transport of the paper P are stopped between scanning processes so that the time interval between the start of a scanning process and the start of the next scanning process is the original time interval without dirt reduction control plus the waiting time. When either the first or second cumulative usage length is used as the cumulative usage length, the control unit 9 provides a waiting time between scanning processes for the entire sheet of paper P, the length obtained based on the first or second cumulative usage length. When the third cumulative usage length is used as the cumulative usage length, the third cumulative usage length is obtained for the position where that scanning process (i.e., the next image recording) is performed each time a scanning process is performed. Then, a waiting time is provided between each scanning process and the next scanning process, the waiting time being determined based on the table of FIG. 5 and corresponding to the acquired third cumulative usage length.

[0054] According to the present embodiment described above, the dirt reduction control is performed by executing at least one of the following: (1) control to reduce the amount of ink ejected from the head 5; and (2) control to provide a waiting time between a scanning process and the next scanning process during image recording. Process (1) reduces the amount of ink, thereby suppressing the occurrence of the phenomenon in which the paper P floats up when the ink ejected from the head 5 reaches the paper P. Process (2) also provides a waiting time between scanning processes, so even if the paper P floats up due to one scanning process, the floating is likely to subside before the next scanning process. Therefore, in either case, dirt on the paper surface is suppressed.

[0055] In this embodiment, the ink ejection rate in process (1) or the waiting time in process (2) is adjusted as a parameter for the contamination reduction control based on the paper type, cumulative usage length, and roller grip status. Of these, the paper type, which corresponds to the characteristics of the paper P, and the cumulative usage length, which corresponds to the usage status of the paper P, are both information related to the degree to which the paper P will curl. Regarding paper type, roll paper Rp is more likely to curl than cut paper Kp. Regarding cumulative usage length, considering that the roll paper Rp is unwound from a roll R, in which a long length of paper is wound around a core Rc, the greater the cumulative usage length, the greater the degree of curl. When paper P curls, it is more likely to come into contact with the head 5, and the risk of contact increases as the degree of curl increases. Therefore, by adjusting the content of the contamination reduction control based on the paper type and cumulative usage length, which are information related to the occurrence of curl, as described above, contamination reduction control can be performed according to the curl status.

[0056] Furthermore, the roller nipping state affects the likelihood that the paper P will come into contact with the head 5 while being transported by the transport roller pair 23 and the paper discharge roller pair 24. In other words, when the medium is nipped between both of the transport roller pair 23 and the paper discharge roller pair 24, there is a lower risk that the paper P will come into contact with the liquid ejection head between the nipping positions of the two roller pairs, compared to when the medium is nipped between only one of the roller pairs. Therefore, by adjusting the content of the dirt reduction control according to the nipping state of the two roller pairs, it is possible to execute the dirt reduction control to a degree appropriate to the risk of dirt occurring.

[0057] In this embodiment, contamination reduction control is performed according to Tables 4 and 5. As described above, Tables 4 and 5 show that roll paper reduces the ink ejection amount to a greater extent and has a longer waiting time than cut paper. Furthermore, the greater the cumulative usage length, the greater the reduction in ink ejection amount and the longer the waiting time. The greater the reduction in ejection amount, the more curling is suppressed, and the longer the waiting time, the less likely the paper P will come into contact with the head 5. The more curling and contact of the paper P with the head 5 are suppressed, the more contamination on the paper P is suppressed. In other words, Tables 4 and 5 are adjusted to ensure the contamination reduction effect within an appropriate range depending on the degree of curl. Furthermore, when only one of the conveying roller pair 23 and the paper discharge roller pair 24 is clamping the paper P, the greater the reduction in ink ejection amount and the longer the waiting time, compared to when both are clamping the paper P. In other words, Tables 4 and 5 are adjusted to ensure the contamination reduction effect within an appropriate range depending on the clamping state of the roller pair. Therefore, by adjusting the parameters based on Tables 4 and 5, the dirt reduction control is executed appropriately to a degree corresponding to the risk of dirt generation.

[0058] [Second embodiment] A printer 200 according to a second embodiment, which is another embodiment of the present invention (corresponding to the "liquid ejection device" of the present invention), will be described with reference to Fig. 6. The difference between the printer 200 and the printer 100 according to the first embodiment is that the printer 200 is provided with a head 205 and a control unit 209 instead of the head 5 and the control unit 9. Hereinafter, the same reference numerals as above will be used as appropriate for the components of the printer 200 that are common to the printer 100, and descriptions thereof will be omitted as appropriate.

[0059] The head 205 (corresponding to the "liquid ejection head" of the present invention) includes a plurality of nozzles 51 (see FIG. 2) formed on the bottom surface, and a driver IC. When the driver IC is driven under the control of the control unit 209, ink is ejected from the nozzles 51, and an image is recorded on the paper P when the paper P, transported by the transport mechanism 2, passes through an image recording position facing the bottom surface of the head 205.

[0060] While the head 5 according to the first embodiment is a serial type that ejects ink from the nozzles 51 while moving in the scanning direction, the head 205 is a line type head that ejects ink from the nozzles 51 while remaining in a fixed position.

[0061] The control unit 209 controls the entire printer 200. Similar to the control unit 9, the control unit 209 is electrically connected to the feed motor 21a, intermediate motor 22a, transport motor 23a, discharge motor 24a, cutting motor 3a, driver IC, roll body sensor 71, feed position sensor 72, leading edge position sensor 81, rotary encoder 82, etc. The operation speeds of the feed motor 21a, intermediate motor 22a, transport motor 23a, and discharge motor 24a are controlled by the control unit 209. This allows the control unit 209 to control the transport speed of the paper P by the transport mechanism 2.

[0062] The control unit 209, like the control unit 9, includes a CPU, a ROM, a RAM, an ASIC, etc. The various fixed data stored in the ROM includes data showing a table showing the relationship between the paper type, the cumulative usage length, the roller clamping state, and the conveying speed of the paper P, instead of the tables of FIGS.

[0063] The control unit 209 records an image on the paper P based on a recording instruction sent by a user from an external device (for example, a PC or a smartphone). Image recording is performed by ejecting ink from the multiple nozzles 51 of the head 205 simultaneously with a transport process in which the transport mechanism 2 transports the paper P in the transport direction. The ink is ejected toward the paper P that is moving in the transport direction as it is transported by the transport mechanism 2.

[0064] The control unit 209 executes (3) control to reduce the conveying speed as the dirt reduction control. That is, the control unit 209 reduces the conveying speed of the paper P during image recording compared to when dirt reduction control is not executed. In the dirt reduction control, the control unit 209 executes processes to determine the paper type, acquire the cumulative used length, and acquire the roller clamping status, just like the control unit 9. Then, based on the determination results and calculation results, the control unit 209 acquires the conveying speed from a table indicated by data stored in ROM, and controls image recording so that the paper P is conveyed at the acquired conveying speed. This table contains the following information regarding the paper type: the conveying speed for roll paper is slower than for cut paper, the conveying speed decreases as the cumulative used length increases, and the conveying speed for the roller clamping status is slower for "one roller" than for "two rollers." Furthermore, all of the conveying speeds acquired from the table are smaller than when dirt reduction control is not executed. As a result, when the paper P is transported, the transport speed is reduced compared to when the dirt reduction control is not performed, and the transport speed for roll paper is slower than for cut paper in terms of paper type, the transport speed becomes slower as the cumulative usage length increases, and the transport speed for the roller clamping condition is controlled to be slower for "one roller" than for "two rollers."

[0065] According to the above-described configuration of this embodiment, the control unit 209 executes (3) control to reduce the conveying speed as a stain reduction control. Even if the sheet P lifts up once, a slower conveying speed makes it easier for the lifting to settle. This suppresses the occurrence of stains on the sheet surface. Furthermore, since the conveying speed is reduced in accordance with the sheet type and cumulative usage length, which are information related to the occurrence of curl, stain reduction control can be executed in accordance with the curl status. Furthermore, since the conveying speed is reduced in accordance with the clamping status of the two roller pairs, stain reduction control can be executed to a degree corresponding to the risk of stain occurrence.

[0066] <Modification> Although the embodiments of the present invention have been described above with reference to the drawings, the specific configurations should not be considered to be limited to these embodiments. The scope of the present invention is defined by the claims rather than the above description of the embodiments, and further includes all modifications within the meaning and scope of the claims.

[0067] [1] In the first embodiment described above, a waiting time is provided between scanning processes, and the time interval between the start of one scanning process and the start of the next scanning process is increased by this time, thereby performing the stain reduction control (2). Other methods may be used to increase the time interval. For example, a method may be used to adjust the movement speed of the carriage 4 in the process of moving the carriage 4 from the position at the end of one scanning process to the position at the start of the next scanning process. In this case, reducing the movement speed corresponds to increasing the time interval. Alternatively, a method may be used to adjust the transport speed of the paper P in the transport process (the process of transporting the paper P a predetermined distance in the transport direction) performed between scanning processes. In this case, reducing the transport speed corresponds to increasing the time interval. In either case, increasing the time interval between the start of a scanning process and the start of the next scanning process makes it easier for the paper P to settle down before the next scanning process, even if it is temporarily lifted by one scanning process. Therefore, the occurrence of stains on the paper P is reduced.

[0068] [2] In the first and second embodiments described above, the parameters are adjusted so that the effect of the dirt reduction control is stronger in the "one roller" roller sandwiching state than in the "two rollers" roller sandwiching state. Additionally or alternatively, in the "one roller" roller sandwiching state, the parameters of the dirt reduction control may be adjusted depending on whether the conveying roller pair 23 or the discharge roller pair 24 sandwiches the paper P.

[0069] For example, if the paper P is roll paper Rp, and the paper P is unwound from a roll R, which is a long piece of paper wound around a core member Rc, the curl of the paper P will be stronger in the upstream direction of the transport. Therefore, a single sheet of roll paper Rp separated from the roll R will tend to curl more strongly near its rear end in the transport direction than near its front end. Meanwhile, when only the transport roller pair 23 holds the paper P during image recording, this corresponds to a situation in which a portion of the single sheet of roll paper Rp relatively close to the leading edge faces the head 5. In contrast, when only the discharge roller pair 24 holds the paper P during image recording, this corresponds to a situation in which a portion of the single sheet of roll paper Rp relatively close to the trailing edge faces the head 5. Therefore, when only the discharge roller pair 24 holds the paper P, there is a higher risk of the paper P coming into contact with the head 5 than when only the transport roller pair 23 holds the paper P.

[0070] Therefore, when the roller clamping state corresponds to "one roller," it is preferable to adjust the parameters so that contact of the paper P with the head 5 is more suppressed when the paper discharge roller pair 24 arranged downstream in the conveying direction clamps the paper P (hereinafter referred to as "when the paper discharge rollers clamp") than when the paper transport roller pair 23 arranged upstream in the conveying direction clamps the paper P (hereinafter referred to as "when the paper transport rollers clamp"). In other words, it is preferable to increase the degree of reduction in the discharge amount in the dirt reduction control (1) according to the first embodiment and to lengthen the waiting time in the dirt reduction control (2) when the paper is clamped by the paper discharge rollers compared to when the paper is clamped by the conveying rollers. Furthermore, it is preferable to reduce the conveying speed of the paper P when the paper is clamped by the paper discharge rollers compared to when the paper is clamped by the conveying rollers in the dirt reduction control (3) according to the second embodiment. This makes it possible to execute the dirt reduction control to a degree appropriate to the risk of dirt generation.

[0071] [3] Parameters may be adjusted based not only on the state of sandwiching the paper P between the pair of conveying rollers 23 and the pair of paper discharge rollers 24, but also on the influence of the surrounding configuration on the state of the paper P. For example, the influence of the platen 40 and corrugated plate 41 shown in FIG. 7 on the paper P may be taken into consideration. The platen 40 has a roughly rectangular parallelepiped shape and is positioned to face the head 5 in the vertical direction. The platen 40 supports the paper P conveyed to a position facing the head 5 on its upper surface. A plurality of ribs 40a are formed on the upper surface of the platen 40 at equal intervals in the scanning direction. The ribs 40a are flat protrusions that protrude upward from the platen 40 and are positioned so that their thickness direction is aligned with the scanning direction. The corrugated plate 41 is alternately arranged with the ribs 40a at equal intervals in the scanning direction. The corrugated plate 41 is positioned slightly forward of the pair of conveying rollers 23. The lower end of the corrugated plate 41 faces the upper surface of the platen 40 with a small gap therebetween. The lower end of the corrugated plate 41 is located slightly below the upper end of the rib 40a.

[0072] As the paper P is transported by the transport mechanism 2, it passes over the ribs 40a near the downstream side of the transport roller pair 23 and simultaneously passes through the gap between the lower end of the corrugated plate 41 and the upper surface of the platen 40. At this time, the lower end of the corrugated plate 41 presses the paper P downward, causing it to curve downward. Also, the upper ends of the ribs 40a lift the paper P upward, causing it to curve upward. This causes the paper P to assume a wavy shape in the scanning direction.

[0073] Due to the action of the platen 40 and corrugated plate 41 on the sheet P, the sheet P maintains a stable shape near the downstream side of the pair of transport rollers 23. On the other hand, there is no structure for stabilizing the shape of the sheet P near the pair of discharge rollers 24. Therefore, when the sheet P is sandwiched only by the pair of transport rollers 23, the sheet P is kept stable only by the pair of transport rollers 23 and their vicinity. In contrast, when the sheet P is sandwiched only by the pair of discharge rollers 24, the sheet P is supported by the pair of discharge rollers 24 and is kept relatively stable also near the pair of transport rollers 23. Therefore, in the former state, it is more difficult to prevent the sheet P from floating up in the area between the pair of transport rollers 23 and the pair of discharge rollers 24 than in the latter state. Therefore, considering the effects of the platen 40 and the corrugated plate 41 on the paper P, when the roller clamping state is "one roller," the dirt suppression control is executed to more effectively prevent the paper P from contacting the head 5 when the paper P is sandwiched by the conveying rollers than when the paper P is sandwiched by the discharge rollers. This makes it possible to execute the dirt reduction control to a degree appropriate to the risk of dirt. Furthermore, when the corrugated plate 41 is relatively effective in stabilizing the shape of the paper P, the risk of dirt occurring may be lower when the paper P is not sandwiched between the pair of paper discharge rollers 24 and the paper P is passing through the gap between the lower end of the corrugated plate 41 and the upper surface of the platen 40 than when the paper P is sandwiched only by the pair of paper discharge rollers 24. In such a case, the dirt reduction control is executed to more effectively prevent the paper P from contacting the head 5 in the former state than in the latter state. This makes it possible to execute the dirt reduction control to a degree appropriate to the risk of dirt occurring. The latter state applies regardless of whether the paper P is sandwiched between the pair of paper discharge rollers 23 or not.

[0074] [4] According to the first and second embodiments described above, parameters for the dirt reduction control are adjusted according to at least one of the paper type, cumulative usage length, and roller grip state. Alternatively, or in addition, a configuration may be adopted in which parameters are adjusted based on the detection results of a sensor that directly detects the degree of curl of the paper P. Such a sensor may be, for example, an optical sensor installed to the side of the feed path or transport path of the paper P. The optical sensor detects the degree to which the paper P is lifted or deviated from the correct path. The control unit 9 or 209 then adjusts various parameters for the dirt reduction control to values ​​according to the degree of lifting or deviation indicated by the detection results of the optical sensor. The detection results of the optical sensor correspond to the "medium information" of this invention.

[0075] [5] In the first embodiment described above, the contamination reduction control includes at least one of (1) reducing the amount of ink ejected from the head 5 and (2) providing a waiting time between scanning operations during image recording. Alternatively, or in addition, the contamination reduction control may include increasing the image recording resolution. Increasing the image recording resolution results in more frequent interlacing and shingling operations. This reduces the amount of ink ejected per scanning operation and the transport distance of the paper P per transport operation. This reduces the likelihood of the paper P floating up and contacting the head 5, thereby reducing the occurrence of contamination on the paper P. In this control, the resolution may be adjusted based on at least one of the paper type, cumulative usage length, and roller gripping state. Adjusting the resolution adjusts both the degree of reduction in the amount of ink ejected per scanning operation and the degree of reduction in the transport distance of the paper P per transport operation.

[0076] [6] In addition, in the above-described embodiments, the present invention is described as being applied to the printer 100, but is not limited to this. The present invention can also be applied to multifunction machines, copiers, and other inkjet image recording devices that eject ink from a head. [Explanation of symbols]

[0077] 2. Transport mechanism 4 carriages 5, 205 head (recording unit) 6 Moving mechanism 8 Cartridge mounting section 9, 209 Control section 10 Ink cartridges 51 nozzles 100, 200 Printer (image recording device) P Paper (recording medium)

Claims

1. a medium storage unit that stores sheet-like media; a liquid ejection head capable of ejecting liquid; a moving unit that moves the sheet-like medium fed from the medium storage unit relative to the liquid ejection head; a control unit; and the moving unit is capable of at least a first movement operation of moving a sheet-like medium in a first direction and a second movement operation of moving the liquid ejection head in a second direction perpendicular to the first direction, The medium storage section has a first portion capable of storing a roll of a long sheet medium wound in a roll shape, and a second portion capable of storing a plurality of stacked sheet media shorter than the long sheet medium, the long sheet medium and the short sheet medium are selectively fed from the medium storage unit toward the liquid ejection head; The control unit The first moving operation, the ejection operation, and the second moving operation are alternately and repeatedly performed, or the ejection operation and the first moving operation are simultaneously performed, At least one of the amount of liquid ejected from the liquid ejection head in the ejection operation, the time interval between the start of the ejection operation and the start of the next ejection operation when the first movement operation, the ejection operation, and the second movement operation are performed alternately and repeatedly, and the speed of movement of the sheet medium by the first movement operation when the ejection operation and the first movement operation are performed simultaneously is adjusted so as to suppress contact of the sheet medium with the liquid ejection head, according to medium information related to the occurrence of curl in the sheet medium and indicating at least one of the characteristics and usage status of the sheet medium fed from the medium storage unit, A liquid ejection device characterized in that the medium information indicates as the characteristic whether the sheet medium fed from the medium storage section is the long sheet medium or the short sheet medium.

2. a medium storage unit that stores sheet-like media; a liquid ejection head capable of ejecting liquid; a moving unit that moves the sheet-like medium fed from the medium storage unit relative to the liquid ejection head; a control unit; and the moving unit is capable of at least a first movement operation of moving a sheet-like medium in a first direction and a second movement operation of moving the liquid ejection head in a second direction perpendicular to the first direction, the medium storage unit is capable of storing a roll of a long sheet medium wound in a roll shape, The control unit The first moving operation, the ejection operation, and the second moving operation are alternately and repeatedly performed, or the ejection operation and the first moving operation are simultaneously performed, At least one of the amount of liquid ejected from the liquid ejection head in the ejection operation, the time interval between the start of the ejection operation and the start of the next ejection operation when the first movement operation, the ejection operation, and the second movement operation are performed alternately and repeatedly, and the speed of movement of the sheet medium by the first movement operation when the ejection operation and the first movement operation are performed simultaneously is adjusted so as to suppress contact of the sheet medium with the liquid ejection head, according to medium information related to the occurrence of curl in the sheet medium and indicating at least one of the characteristics and usage status of the sheet medium fed from the medium storage unit, A liquid ejection device characterized in that the medium information indicates the cumulative usage length of the long sheet medium since it was first unwound from the roll stored in the medium storage section and used as the usage status.

3. The long sheet medium is discharged to the outside of the device as a single sheet medium separated from the roll body, The liquid ejection device described in claim 2, characterized in that the control unit adjusts at least one of the amount of liquid in each sheet of sheet medium, the time interval, and the speed of movement of the sheet medium in accordance with the medium information indicating the cumulative usage length up to either the leading end or the trailing end of each sheet of sheet medium.

4. the first moving operation is an operation of moving the sheet medium by a first length in the predetermined direction, the ejection operation is an operation of ejecting liquid onto an area of ​​the sheet medium at intervals of a second length in the predetermined direction, The long sheet medium is discharged to the outside of the device as a single sheet medium separated from the roll body, The liquid ejection device described in claim 2, characterized in that the control unit adjusts at least one of the amount of liquid in the area, the time interval, and the speed of movement of the sheet-like medium in accordance with the medium information indicating the cumulative usage length up to the area for each second length on each sheet-like medium.

5. a medium storage unit that stores sheet-like media; a liquid ejection head capable of ejecting liquid; a moving unit that has a first roller pair that moves the sheet medium fed from the medium storage unit along a predetermined transport direction while sandwiching the sheet medium, and a second roller pair that moves the sheet medium moved by the first roller pair along the predetermined transport direction while sandwiching the sheet medium downstream of the first roller pair in the predetermined transport direction, and moves the sheet medium fed from the medium storage unit relative to the liquid ejection head; a control unit; and the moving unit is capable of at least a first movement operation of moving a sheet-like medium in a first direction and a second movement operation of moving the liquid ejection head in a second direction perpendicular to the first direction, The control unit The first moving operation, the ejection operation, and the second moving operation are alternately and repeatedly performed, or the ejection operation and the first moving operation are simultaneously performed, At least one of the amount of liquid ejected from the liquid ejection head in the ejection operation, the time interval between the start of the ejection operation and the start of the next ejection operation when the first movement operation, the ejection operation, and the second movement operation are alternately repeated, and the speed of movement of the sheet medium by the first movement operation when the ejection operation and the first movement operation are performed simultaneously is adjusted so as to suppress contact of the sheet medium with the liquid ejection head, depending on whether both of the first roller pair and the second roller pair are clamping the sheet medium or whether only one of them is clamping the sheet medium; A liquid ejection device characterized in that when only one of the first roller pair and the second roller pair is clamping the sheet-like medium, at least one of the amount of liquid, the time interval, and the speed of movement of the sheet-like medium is adjusted so as to more effectively suppress contact of the sheet-like medium with the liquid ejection head when one of the first roller pair and the second roller pair is clamping the sheet-like medium compared to when the other is clamping the sheet-like medium.

6. a medium storage unit that stores sheet-like media; a liquid ejection head capable of ejecting liquid; a moving unit that moves the sheet-like medium fed from the medium storage unit relative to the liquid ejection head; a control unit; and the moving unit is capable of a first moving operation of moving a sheet medium in a first direction and a second moving operation of moving the liquid ejection head in a second direction perpendicular to the first direction, The medium storage section has a first portion capable of storing a roll of a long sheet medium wound in a roll shape, and a second portion capable of storing a plurality of stacked sheet media shorter than the long sheet medium, the long sheet medium and the short sheet medium are selectively fed from the medium storage unit toward the liquid ejection head; The control unit The first moving operation, the ejecting operation, and the second moving operation are alternately and repeatedly performed; at least one of the amount of liquid ejected from the liquid ejection head in the ejection operation and the amount of movement of the sheet medium in the first movement operation between the start of the ejection operation and the start of the next ejection operation is adjusted so as to suppress contact of the sheet medium with the liquid ejection head in accordance with medium information related to the occurrence of curl in the sheet medium and indicating at least one of the characteristics and usage status of the sheet medium fed from the medium storage unit; A liquid ejection device characterized in that the medium information indicates as the characteristic whether the sheet medium fed from the medium storage section is the long sheet medium or the short sheet medium.

7. a medium storage unit that stores sheet-like media; a liquid ejection head capable of ejecting liquid; a moving unit that moves the sheet-like medium fed from the medium storage unit relative to the liquid ejection head; a control unit; and the medium storage unit is capable of storing a roll of a long sheet medium wound in a roll shape, the moving unit is capable of a first moving operation of moving a sheet medium in a first direction and a second moving operation of moving the liquid ejection head in a second direction perpendicular to the first direction, The control unit The first moving operation, the ejecting operation, and the second moving operation are alternately and repeatedly performed; at least one of the amount of liquid ejected from the liquid ejection head in the ejection operation and the amount of movement of the sheet medium in the first movement operation between the start of the ejection operation and the start of the next ejection operation is adjusted so as to suppress contact of the sheet medium with the liquid ejection head in accordance with medium information related to the occurrence of curl in the sheet medium and indicating at least one of the characteristics and usage status of the sheet medium fed from the medium storage unit; A liquid ejection device characterized in that the medium information indicates the cumulative usage length of the long sheet medium since it was first unwound from the roll stored in the medium storage section and used as the usage status.

8. a medium storage unit that stores sheet-like media; a liquid ejection head capable of ejecting liquid; a moving unit that has a first roller pair that moves the sheet medium fed from the medium storage unit along a predetermined transport direction while sandwiching the sheet medium, and a second roller pair that moves the sheet medium moved by the first roller pair along the predetermined transport direction while sandwiching the sheet medium downstream of the first roller pair in the predetermined transport direction, and moves the sheet medium fed from the medium storage unit relative to the liquid ejection head; a control unit; and the moving unit is capable of a first moving operation of moving a sheet medium in a first direction and a second moving operation of moving the liquid ejection head in a second direction perpendicular to the first direction, The control unit The first moving operation, the ejecting operation, and the second moving operation are alternately and repeatedly performed; at least one of the amount of liquid ejected from the liquid ejection head in the ejection operation and the amount of movement of the sheet medium in the first movement operation between the start of the ejection operation and the start of the next ejection operation is adjusted so as to suppress contact of the sheet medium with the liquid ejection head, depending on whether both of the first roller pair and the second roller pair are holding the sheet medium or whether only one of them is holding the sheet medium; A liquid ejection device characterized in that when only one of the first roller pair and the second roller pair is clamping the sheet-like medium, at least one of the amount of liquid and the amount of movement of the sheet-like medium is adjusted so as to more effectively suppress contact of the sheet-like medium with the liquid ejection head when one of the first roller pair and the second roller pair is clamping the sheet-like medium compared to when the other is clamping the sheet-like medium.

Images